Answer:
The answer is 380.
Explanation:
Significant figures:
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.06 in this number only one significant figure present which is 6.
Zero between the non zero digits is consider significant like 108 consist of three significant figures.
The zeros at the right side e.g 6300 are also significant. There are four significant figures are present.
How to round the value to three significant figures.
First of all we will place the vertical line after 3rd digit.
379/5
Now we will look at the 4th digit. If it is five or more than five then one is added to 3rd digit. If it is less than five the 3rd digit remain same. In given value 4th digit is 5 thus one is added into 9 and the value become 380.
The answer is 380.
Answer:
it is B because the other answers logically dont fit in
The Law of Conservation of Mass
Oxygen gas produced : 0.7 g
<h3>Further explanation</h3>
Given
10.0 grams HgO
9.3 grams Hg
Required
Oxygen gas produced
Solution
Reaction⇒Decomposition
2HgO(s)⇒2Hg(l)+O₂(g)
Conservation of mass applies to a closed system, where the masses before and after the reaction are the same
mass of reactants = mass of products
mass HgO = mass Hg + mass O₂
10 g = 9.3 g + mass O₂
mass O₂ = 0.7 g
